Proportion attributable to medical care of the reduction in stomach cancer deaths in Miyagi, Japan.

To estimate the contribution of medical care to the reduction in stomach cancer deaths, the trends of incidence and death rates were compared from 1960 to 1970 and from 1970 to 1980 in Miyagi, Japan. The mortality data were derived from the reports by Miyagi Prefectural Government. The incidence data from the Miyagi Prefectural Cancer Registry were used after being adjusted by the proportion of DCO (death certificate only), which is one of the indices of the reliability of the cancer registry. The time lag of 1.2 years was considered when these trends were compared. The proportion attributable to medical care of the reduction from 1960 to 1970 was estimated to be 13.6% for males and 8.2% for females in those 40 years of age or older. The proportion from 1970 to 1980 was estimated to be 17.9% for males and 11.0% for females. Medical care reduced stomach cancer deaths, to be 17.9% for males and 11.0% for females. Medical care reduced stomach cancer deaths, which exceeded the decrease in the total incidence, although it was not possible to estimate the proportions attributed to early detection and to improvement of the treatment methods.